HOUSES THAT HEAT AND COOL THEMSELVES – NATURALLY
‘Sustainability’ is a word common place in the realm of architecture. Many aspects of design and construction contribute to the overall carbon footprint of a building.
At KA we believe that passive solar design plays a crucial part in this equation. Solar access, thermal mass, natural ventilation and insulation are the building blocks of functional architecture. Naturally comfortable, healthy homes that don’t need auxiliary heating or mechanical ventilation are a product of good design. Below are two case studies from our portfolio that showcase how these methods have been implemented in residential and commercial work.
CASE STUDY 1 (RESIDENTIAL) – QUEENSTOWN HOUSE
Client’s words:
“All in all, the house has performed exceptionally well, to be fair. It’s very, very warm in winter and very, very cool in summer. It’s not mechanically ventilated, so relies on natural ventilation, so perhaps during the cross seasons, autumn and spring, where you might get an unseasonably hot day, we just open a few more doors. But typically it’s been designed for that and it’s worked particularly well.”
The client brief required a sustainable, single storey, contemporary, four bedroom country house on a flat site, surrounded by mountain ranges.
Solar access here has been achieved through proper orientation of the building to maximise solar gain with living spaces to the north, as well as soffit design. Per the diagram below, the soffits are angled upwards to guide the winter sun deep into the building, whilst the large overhangs protect from the summer sun, keeping the house cool. This is enhanced through high level opening windows which induce stack ventilation.
The roof panes are connected by a large central gutter that discharges into water tanks. The twist of the southern part of the roof allows for the perfect solar PV panel orientation.
The conservatory space design utilises a glass roof and a tiled concrete slab floor which performs as ground thermal mass, absorbing and storing heat during the day and releasing it at night. This space helps produce passive heating for the whole house and allows the clients to grow sub-tropical plants.
The sculptural form responds to the surrounding environment via push and pull of the façade, creating a series of spaces along the wrap around deck. When the full height glazing is retracted, the home opens up to create a seamless indoor/ outdoor flow.
The entire house has triple glazing and high thermal insulation (well beyond the minimum NZ code requirements) to store the winter heat and keep out the summer heat.
CASE STUDY 2 (COMMERCIAL) – TAKANINI FAMILY SERVICE CENTRE
The client comments:
“The Takanini Family Service Centre was designed by Kamermans Architects Ltd. to provide a “state of the art” community building using affordable and sustainable materials. The building was beautifully designed to be naturally warm in the winter and cool in the summer with wide eaves that control the seasonal sun access to the attractive insulated polished concrete floors. Summer cooling is enhanced through well designed opening windows allowing natural ventilation. Another important feature of our community building was a system that captured our roof water and redistributed it to water the gardens and flush the toilets, thus enhancing our ability to reduce our ecological foot print as well as costs. Through clever design, storage, bathrooms, kitchens etc were confined to the south side of the building leaving the warm and brightly lit north side of the building for the areas that people work and live in. With careful design and a willingness to take a risk in what was a new way of designing conventional buildings, we achieved a beautiful, comfortable, affordable and sustainable “state of the art” building that is a pleasure to work and live in.”
Our brief was to design a low cost building to accommodate three functions:
a. Kindergarten for 100 children aged from 6 months to 5 years old.
b. Family Centre, providing medical, counselling, adult education, meeting room and other community facilities.
c. Headquarters for the Counties Manukau Kindergarten Association, the client.
The functions are expressed as three single storey pavilions. The pavilions are stretched east to west. “People” spaces arranged along the north side with the “service” spaces generally along the south side. The pavilions are expressed as simple sculptural volumes that “reach for the sun”. Wide eaves to the north and the narrow depth of the pavilions give good passive solar heating and cooling. Per the diagrams below the width of the soffits protects from the summer sun, whilst the angle of the soffits allows for the winter sun to penetrate deep into the building. This is, as it is in our residential case study, enhanced through high level opening windows which induce stack ventilation. Large areas of polished concrete floors are ground thermal mass that performs as a heat sink in winter.
Rainwater is harvested for toilet flushing and garden irrigation and car park rain water drains into rain gardens. PV panels on the roof provide supplementary power. Double glazing and high spec thermal insulation store the winter heat and keep out the summer heat. All the sustainable features have been expressed in the architecture to allow them to become part of the educational process.
